Need advice on LED mix

Already bought the veros - got the 3000K 97 CRI ones, which are the coolest 97 CRI they do (I think!).

There are two reasons for looking to under drive them, and that doesn't include the little bonus of increased efficiency (which, as you say, is not massive). Mainly keeping heat production low as they will be going into an enclosed hood (and I hope to have the fans off most of the time), and, when I upgrade in a year or so, I'm hoping I can just swap a few jumpers round on O2Surplus' wonderful driver board, swap a few LDDs and then spread out the 4 clusters to light a much bigger tank :)

That hope in mind (& yes, I know I'm quite likely to simply build a new light at that stage, as it gives me chance to play again, with the new LEDs which will be out by then! But it's still part of the brief I'm following for now...) I want to build 4 units the same. And I need to keep an eye on light spread to avoid rainbow affect. Shouldn't be too bad, but was (slightly) noticeable just using my test panel (3 XML (1 each of WW, NW & CW), 3 XTE RB and 3 XPE B). Hopefully be reduced when using 4 panels. But does make me think it might be more noticable if using smaller number of light sources (eg 8up luxeon Ks) rather than lots of sources mixed together on 20mm stars.

I will have a look at the Luxeon K and Ts :)

Tim
 
SoFloReefer said:
I've never personally used red and green LEDs. I've only used whites: cool, neutral, and warm, and Blues. I've heard of the "disco ball effect" but never seen it and I've built several fixtures. Maybe the solution for you is to go with whites that cover more of that red and green spectrum you are looking for. Also, put the white emitters directly next to blue ones.
Click to expand...
There was an article a year or 2 ago covering light-penetrating spectrums for reefs. Without going into details, the verdict was that blue and violet are the highest absorbed colors. 6500K bulbs gave a high-saturation wl of 444.6nm and 5500k bulbs put out the highest wl at 525.2nm. Considering that 400-440nm is the highest rate of absorption for corals, and not wanting to neglect the other spectrums (but wanting to focus where it si needed), I would expect to see lights with a (roughly) following layout:

12 LED Puck:

3x 6500K White (covers lower blue spectrum)
1x 5500K White (covers green spectrum)
2x 460nm Royal Blue (covers mid-blue spectrum)
2x 440nm Bright Blue (covers high blue spectrum)
2x 420 Pure Violet (covers mid-violet spectrum)
1x 400nm Ultra Violet (covers high violet/UV spectrum)
1x 660nm Deep Red (covers low red spectrums)

Certainly, these could change. Some want to add green for coloration. The green spectrum will be made up in the 5500K, which puts out a dominant wavelength of 525.4nm. Some may want more UV for that effect. In the end, I would think that this should be the basis of a light, and we would ADD more LEDs to it to bring out the effect that we want. This way, the corals get their basic requirements, and we get the look we want out of our tank. That being said, that would require a more expensive fixture, as the added LEDs would only be for show, and would provide minimal, albeit some, positive effect on coral growth and health.
 
Meddler said:
3x 6500K White (covers lower blue spectrum)
1x 5500K White (covers green spectrum)
2x 460nm Royal Blue (covers mid-blue spectrum)
2x 440nm Bright Blue (covers high blue spectrum)
2x 420 Pure Violet (covers mid-violet spectrum)
1x 400nm Ultra Violet (covers high violet/UV spectrum)
1x 660nm Deep Red (covers low red spectrums)
Click to expand...
I think, this changes will be useful:
1. Royal blue should have wavelength not more that 450nm, preferably 445-450nm. Longer wavelength is not good for fluorescence.
2. PC Amber should be added to increase visual appearance of "warm" not-fluorescent colors. If you will add PC Amber, please remove from set 5500K LED.
3. 440nm LED looks as very dark blue, i.e. darker than royal blue, but not as dark as violet. Will be better remove this LED and increase 420nm (410-420nm is the best option) up to 4pcs.
4. Please beware with 400nm LED. Some type of it may have significant amount of radiation near to 380nm, this radiation may cause some fluorescence of small particles in water, it is looks very bad. I advice you to use 400-410nm, not shorter wavelength.
5. 660nm LED should be used with care. Too much of radiation with this wavelength may cause unwanted algae. Best options is 630-645nm LED, if you can't find it, please use 620-630nm LED.
6. Blue LED 470-475nm should be added in any case. This wavelength is corrects the lack of this part of spectrum in all types of white LEDs.

There are also several niceties, that may be important for you, please familiarise: www.advancedaquarist.com/2014/4/lighting
 
So, you would suggest a basis like this?

3x 6500K White
2x 445-450nm Royal Blue
1x PC Amber
4x 410-420nm Pure Violet
?x 400-410 UV
1x 630-645nm Red
?x 470-475nm Blue

Tim
 
Mostly yes.

You may choose one of this options:
1. No one 400-410nm LEDs and 4pcs 410-420nm LEDs.
2. Only 1pcs of 400-410nm LEDs and 3pcs 410-420nm LEDs.

Regard to blue LED. Only one LED will enough for this set.

Also I would like to ask you again to read article on AA. That article contain many important points, that should know all DIYers to avoid mistake in construction of own LED fixture.
 
ReefLedLab said:
I think, this changes will be useful:
1. Royal blue should have wavelength not more that 450nm, preferably 445-450nm. Longer wavelength is not good for fluorescence.
2. PC Amber should be added to increase visual appearance of "warm" not-fluorescent colors. If you will add PC Amber, please remove from set 5500K LED.
3. 440nm LED looks as very dark blue, i.e. darker than royal blue, but not as dark as violet. Will be better remove this LED and increase 420nm (410-420nm is the best option) up to 4pcs.
4. Please beware with 400nm LED. Some type of it may have significant amount of radiation near to 380nm, this radiation may cause some fluorescence of small particles in water, it is looks very bad. I advice you to use 400-410nm, not shorter wavelength.
5. 660nm LED should be used with care. Too much of radiation with this wavelength may cause unwanted algae. Best options is 630-645nm LED, if you can't find it, please use 620-630nm LED.
6. Blue LED 470-475nm should be added in any case. This wavelength is corrects the lack of this part of spectrum in all types of white LEDs.

There are also several niceties, that may be important for you, please familiarise: www.advancedaquarist.com/2014/4/lighting
Click to expand...

So my only question here is: I see that you referenece fluorescence, which is a visible emission of light. So while fluorescence is cool, it does not affect the growth, but only the appearance. Therefore, I would be unsure if the changes would only be for visual appeal, or if there is actually a growth factor improvement through those changes?

In short: does increasing fluorescence increase coral health and growth rate? If it does not, then it seems like all of these changes deter from the task at hand, which is coral growth and health. Correct me if I am misunderstanding.
 
While corals are more beautiful when they adsorb near-invisible UV and fluoresce at higher frequencies, I'm not sure they grow faster under low wavelength if the PAR is the same. Green photons radiating at the same PAR as blue photons should result in equivalent growth (assuming the PAR is measured at the same depth in water).
 
karimwassef said:
I found this article that says otherwise

http://www.int-res.com/articles/meps_oa/m364p097.pdf
Click to expand...
Our company before starting the design of components, has studied this matter. In our work we used a lot of scientific papers, including this one. Our results were presented more than one and half years ago in an article at Advancedaquarist, that I indicated above. I sure, conclusion of this study is exact as we wrote in our article, please check article carefully.

While working on the our article, we discussed it with the author of the article that you specified - dr. Jörg Wiedenmann.
 
karimwassef said:
While corals are more beautiful when they adsorb near-invisible UV and fluoresce at higher frequencies, I'm not sure they grow faster under low wavelength if the PAR is the same. Green photons radiating at the same PAR as blue photons should result in equivalent growth (assuming the PAR is measured at the same depth in water).
Click to expand...

PAR measurements are misleading..
95% of the PAR spectrum can be utilized.. Only 5% is used in CO2 uptake.
Click to expand...
.at least for terrestrial plants (I am making an assumption on this for general consideration)
http://meto.umd.edu/~zli/PDF_papers/97JD01219_APAR.pdf
As to the subtleties of various wavelength "efficiencies"
image_full


So in general PAR measured w/ a green light is not equal to say par measured under a blue light.. Blue and red photons are more efficiently captured not to mention some systems other than direct photosynthesis are wavelength dependent..

PAR is a comparative tool and an attempt at "standardization" (which it only begrudgingly achieves) for the sake of comparison..and is not very accurate w/ "monochromatic" or punctated spectrum light.

As to the complexity of what you are attempting to simplify.. an example:
Here we show that the fluorescent pigments3, 4, 5, 6, 7, 8, 9 (FPs) of corals provide a photobiological system for regulating the light environment of coral host tissue. Previous studies have suggested that under low light, FPs may enhance light availability4, 5. We now report that in excessive sunlight FPs are photoprotective; they achieve this by dissipating excess energy at wavelengths of low photosynthetic activity, as well as by reflecting of visible and infrared light by FP-containing chromatophores. We also show that FPs enhance the resistance to mass bleaching of corals during periods of heat stress, which has implications for the effect of environmental stress on the diversity of reef-building corals, such as enhanced survival of a broad range of corals allowing maintenance of habitat diversity.
Click to expand...

http://www.nature.com/nature/journal/v408/n6814/abs/408850a0.html

Neither position i.e "what is good for growth is good for fluorescence" and "green is as good" are both correct and wrong at the same time... ;)

green and UV A are examples.. ;)
. By comparing their distribution between
light- and shade-acclimated corals, we provide evidence that fluorescent granules of corals function as
screens against high U
VA/blue irradiances by absorbing these wavelengths as well as by reflecting a
large proportion of visible light (photosynthetically active radiation,
PAR)
Click to expand...
http://www.reef.edu.au/OHG/HG papers/Salih, Hoegh-Guldberg and Cox et al 1997 - fluoro.pdf

Seems if you want more "color" either starving or shocking seems to work... ;)
So "its complicated" comes to mind.
. The results of our
morphological analysis of fluorescent pigments in high and dim light acclimated corals indicate
differences in the use of FPGs, and provide insights into how corals may modify the irradiance
environment surrounding their symbiotic algae
Click to expand...
 
Sure. Too much of anything is not good and corals tan (UV) or bleach (IR) when things are out of their comfort zone (anywhere in the middle)

I still see no reason (theory) or data that says that a photon at a red wavelength results in a different growth than a photon at blue light. One paper with a few specimens doesn't convince a scientific community.

By the way, I only use blue and UV LEDs myself and would love to believe that it improves my coral growth... But I only use them for vanity's sake (pretty). I expect my very hot, very inefficient 400W Ushio MHs to do the growing.
 
karimwassef said:
Sure. Too much of anything is not good and corals tan (UV) or bleach (IR) when things are out of their comfort zone (anywhere in the middle)

I still see no reason (theory) or data that says that a photon at a red wavelength results in a different growth than a photon at blue light. One paper with a few specimens doesn't convince a scientific community.

By the way, I only use blue and UV LEDs myself and would love to believe that it improves my coral growth... But I only use them for vanity's sake (pretty). I expect my very hot, very inefficient 400W Ushio MHs to do the growing.
Click to expand...

Actually red light might........ ;)

Jan Graefe · Leibniz-Institute of Vegetable and Ornamental Crops
Besides non-chlorophyll light absorption and lower efficiencie of carotenoids there seems to be an other effect for plants and under low light conditions. The quantum yields of PSII and PSI seem to be more balanced under red light (averaged over 600-700 nm) then under blue light (averaged over 400-500 nm). In the absence of any alternative and cyclic electron flows, any imbalance of photosystem I+II excitation (i.e. ratio <>1) will translate to overall reductions in overall linear electron flow. But this is likely modulated by the spectral light distribution during growth, which influences stochiometry of photsystems and by the extent of state transitions.
Moreover, under high light intensities UV/blue light is likely to induce stronger photoinhibition than red light, because quantum efficiency for photoinhibition is higher for UV/blue wavelengths.
Click to expand...
Colored light differences in response re: plants is Botany 101.. There are quantitative and qualitative differences....

M. Khan · University of Tabuk, Tabuk, Saudi Arabia
Blue light is absorbed not only by chlorophyll, but
also by carotenoids, and some carotenoids are not in the chloroplasts;
further, carotenes and xanthophylls make up the carotenoids.. and
Carotenes do not transfer absorbed energy efficiently to chlorophyll, and
thus some part of absorbed light in the blue is not going to
photosynthesis. On the other hand, all of red light is absorbed by
chlorophylls and used effectively.

Answer through email to me by
Prof. (Emiritus) Govindjee
Biochemistry, Biophysics and Plant
Biology,University of Illinois, 265 Morrill Hall,MC-116, 505 South Goodwin
Avenue, Urbana,IL 61801-3707, USA;
Click to expand...

What scientific community doubts this???

As I said.. just shock them (just found this for info:)
UV-A and UV-B light waves do penetrate the water's surface and are filtered out as the light travels through the water. Both UV-A and UV-B light waves have been found to cause destruction of the DNA and RNA within the coral's tissues. In response, many corals have made adaptations in reducing the effects of these harmful rays. Corals have developed protective pigments that are often blue, purple, or pink in color. Most corals that contain these pigments come from shallow waters where the amount of UV-A and UV-B light is higher than in deeper areas of the reef.

In an aquarium, we use glass over metal halide lighting to reflect any UV light before it enters the water. This is important to protect any corals that do not contain these pigments, and to protect the shallow water corals that may have lost their pigments in transportation. It is common for corals with these bright colors to adapt to the lower UV-A and UV-B conditions within the aquarium by losing their colorful pigmentation. This is not a sign of an unhealthy coral; it is simply the adaptation of the coral to its new environment.
Click to expand...
 
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karimwassef said:
Sure. Too much of anything is not good and corals tan (UV) or bleach (IR) when things are out of their comfort zone (anywhere in the middle)
Click to expand...
1. We should NOT use UV radiation shorter ~390nm in our LED fixture, because UV with wavelength shorter than 390nm will cause unwanted glow of small particles in water.
2. Corals not "tan" due to UV radiation. Substance that protects corals from UV is a colorless and transparent.

Bleaching of coral may caused due to many factors, but usually due to high KH jointly with high intensity of light in ULNS.

I still see no reason (theory) or data that says that a photon at a red wavelength results in a different growth than a photon at blue light. One paper with a few specimens doesn't convince a scientific community.
Click to expand...
As you can see in our article on AA, scientific studies has showed that for most SPS coral long-wavelength radiation may cause problem with growth. We think, it is especially often for mid- and deepwater corals.
 
Tan = protective pigments (oreo's post)
Long wavelength (~red) may cause problems - reefled's post
Red may be easier to absorb since it doesn't trigger protective pigmentation - oreo's post

Scientific community = all reef keepers who are eager to learn and experiment (myself included). I happen to be a scientist - just not in the field of corals ;)

Here is what I am hoping exists:

One coral - fragmented into 6 similar pieces in the same tank. Each piece exposed to the same PAR at different frequencies. Experiment runs for 6 months. Data says : xxxxxx

Repeat this with 3 or 4 different corals

Get consistent results

Have the same experiment run by another

Peer review... Publish ....

Is there such a piece of research on this topic?
 
karimwassef said:
Tan = protective pigments (oreo's post)
Long wavelength (~red) may cause problems - reefled's post
Red may be easier to absorb since it doesn't trigger protective pigmentation - oreo's post

Scientific community = all reef keepers who are eager to learn and experiment (myself included). I happen to be a scientist - just not in the field of corals ;)

Here is what I am hoping exists:

One coral - fragmented into 6 similar pieces in the same tank. Each piece exposed to the same PAR at different frequencies. Experiment runs for 6 months. Data says : xxxxxx

Repeat this with 3 or 4 different corals

Get consistent results

Have the same experiment run by another

Peer review... Publish ....

Is there such a piece of research on this topic?
Click to expand...

As I said.. "it's complicated" blanket statements are problematic at best.. esp w/ a symbiotic organism..

Spectrum

The results above demonstrate that different coral species exhibit different growth rates under the two light spectra provided. Interestingly, a positive effect of irradiance on the growth of Stylophora pistillata was only found for the blue-dominant LED spectrum. Under a more balanced LEP spectrum, containing more red and less blue light, S. pistillata already maximized its growth at the lowest irradiance. It is unclear why this occurred, but it may be related to the photosynthetic pigment complement of the specimens used, which could be chromatically adapted to shallow-water conditions where red light is abundant. Indeed, these corals were collected from shallow water in Eilat, Israel. In the same way, chromatic adaptation of the symbiotic zooxanthellae of Acropora millepora to a high-red spectrum may explain why this species grew faster under LEP at the lowest irradiance applied.

Pocillopora damicornis showed negative growth rates under all LED treatments, which was a result of tissue necrosis. It is unclear why this occurred, but it may have been due to limiting water flow rate. As only moderate water flow rates were measured in the systems (below 10 cm s-1), an accumulation of photosynthetic oxygen and heat within the tissue may have resulted in mortality (Fabricius 2006; Mass et al. 2010a). It is known that highly energetic blue light stimulates photosynthesis in zooxanthellae most efficiently (Halldal 1969), which may require higher water flow rates to remove excess oxygen and heat from coral tissue. It is however unclear why the other species in this study did not show such an adverse effect to the high blue LED spectrum.

Montipora aequituberculata exhibited highest growth rates under LED at low irradiance, which contrasts with the results of other species. In a similar way to S. pistillata and A. millepora, this species may be chromatically adapted to a high blue spectrum, which is found in the wild at depths below approximately 10 meters.
Click to expand...

;)

I know of no studies growing corals under monochromatic light but it would be interesting..

Again. PAR is not exactly "quantitative":
The spectrum range which is used for measurement is approximately 400 to 700 nanometers, which is the portion of light that is visible to the human eye. This part of the light spectrum is able to stimulate the photosynthetic pigments residing in plants, and is therefore called Photosynthetically Active Radiation, or PAR. It is not a unit of measurement, but rather a quality that is being measured (such as distance, or time). PUR, photosynthetically Useable Radiation, is that part of the visible light which is actually absorbed by the complement of photoreactive pigments in a given plant. This will differ between plant species, and also for different clades of zooxanthellae. It is therefore not possible to assign a PUR value to a given lamp, as it depends on the organism that is receiving the light. For example, a coral species which inhabits a deep reef is exposed to dim, blue light. For such a species, a light source containing a high amount of blue in its spectrum may provide a lot of PUR. At the same time, this light source may show a low PAR value, if all other colours are emitted in low intensity.
Click to expand...

http://www.coralscience.org/main/articles/symbiosis-4/inside-a-coral-lab

Back to the symbiosis:
The scientists also made a direct comparison between photosynthesis and growth. Figure 4 shows the relation between photosynthesis and specific growth rate. At higher photosynthesis rates, the specific growth rate leveled off. This proved that at higher light intensities, light and photosynthesis were not the limiting factors for coral growth, as coral growth was not proportional to photosynthesis. As the scientists put it; “Thus it seems that enhancement of calcification is not entirely photosynthesis-driven: light enhanced calcification seems only to be mediated by photosynthesis at lower irradiances, while at higher irradiances the relation between calcification and photosynthesis is distorted”.
Click to expand...
http://www.coralscience.org/main/articles/aquaculture-a-husbandry-4/insights-high-irradiance
 
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